害群之马 (hài qún zhī mǎ) is translated to "troublemaker" or "black sheep" in English. The phrase "black sheep" is thought to have originated from the fact that black sheep were considered to be undesirable in a flock of white sheep because they were less valuable for their wool. The phrase "black sheep" is often used to describe a person who does not conform to the expectations of a group or society and may cause trouble or harm to others.
